Earthmoving scrapers commonly have an ejector disposed for fore and aft movement within the scraper bowl for selectively ejecting material therefrom. The efficiency of the ejector is determined in part by the amount of clearance between the ejector and the floor and sidewalls of the scraper bowl with the ejector normally being positioned by a plurality of rollers to maintain such clearance. One of the problems encountered with the roller supported ejector is that of initially centering and positioning the ejector within the scraper bowl to obtain the desired clearance to compensate for manufacturing tolerances and any subsequent readjustment of the ejector to compensate for wear and/or distortion of the ejector or bowl. Heretofore numerous sets of rollers, each roller of which is adjustable laterally relative to its axis, have been utilized with one set employed for adjusting the clearance between the ejector and the sidewalls while another set is employed to adjust the clearance between the ejector and floor. This unduly multiplies the number of rollers required as well as the number of rollers requiring periodic positioning to maintain the proper ejector clearance.